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Food Chemistry Aug 2023The hydrolysis of the water-soluble protein (WSP) fraction from tuna fish meal was evaluated by subcritical water (subW) by using N and CO as different pressurization...
The hydrolysis of the water-soluble protein (WSP) fraction from tuna fish meal was evaluated by subcritical water (subW) by using N and CO as different pressurization agents in the temperature range from 140 to 180 °C. For both gases, the amino group release increased by increasing working temperature while the Lowry response decreased due to production of smaller-size peptides and free amino acids. The free amino acid content was higher with CO than with N. At 180 °C, 344 ± 5 and 275 ± 3 mg of free amino acids per g of WSP were released, respectively; although, in both systems the smallest molecular weight amino acids, glycine and alanine, were preferentially released. The free amino acids content obtained by enzymatic hydrolysis with commercial proteases Alcalase and Novozym was much lower with the highest hydrolysis yield determined for histidine. These results have been supported by size exclusion chromatography analysis.
Topics: Animals; Amino Acids; Water; Molecular Weight; Carbon Dioxide; Peptides; Hydrolysis
PubMed: 37003201
DOI: 10.1016/j.foodchem.2023.135925 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Jan 2022Alginate is a group of polyuronic saccharides that are widely used in pharmaceutical and food industry due to its unique physicochemical properties and beneficial health... (Review)
Review
Alginate is a group of polyuronic saccharides that are widely used in pharmaceutical and food industry due to its unique physicochemical properties and beneficial health effects. However, the low water solubility and high viscosity of alginate hampered its application. Alginate oligosaccharide (AOS) is a decomposition product of alginate and has received increasing attention due to its low molecular weight, high water solubility, safety, and non-toxicity. The wide-ranging biological functions of AOS are closely related to its structural diversity. AOS with distinct structures and biological functions can be obtained by different methods of preparation. This review summarized the biological functions of AOS reported to date, including anti-tumor, immunomodulatory, anti-inflammatory, antioxidant, prebiotic, and anti-diabetes. The preparation of AOS, as well as the relationship between the structure and biological functions of AOS were discussed, with the aim to provide a reference for further development and application of AOS.
Topics: Alginates; Anti-Inflammatory Agents; Antioxidants; Molecular Weight; Oligosaccharides
PubMed: 35142122
DOI: 10.13345/j.cjb.210377 -
Macromolecular Rapid Communications Dec 2022Reversible addition-fragmentation chain transfer (RAFT) polymerization has proven itself as a powerful polymerization technique affording facile control of molecular...
Reversible addition-fragmentation chain transfer (RAFT) polymerization has proven itself as a powerful polymerization technique affording facile control of molecular weight, molecular weight distribution, architecture, and chain end groups - while maintaining a high level of tolerance for solvent and monomer functional groups. RAFT is highly suited to water as a polymerization solvent, with aqueous RAFT now utilized for applications such as controlled synthesis of ultra-high molecular weight polymers, polymerization induced self-assembly, and biocompatible polymerizations, among others. Water as a solvent represents a non-toxic, cheap, and environmentally friendly alternative to organic solvents traditionally utilized for polymerizations. This, coupled with the benefits of RAFT polymerization, makes for a powerful combination in polymer science. This perspective provides a historical account of the initial developments of aqueous RAFT polymerization at the University of Southern Mississippi from the McCormick Research Group, details practical considerations for conducting aqueous RAFT polymerizations, and highlights some of the recent advances aqueous RAFT polymerization can provide. Finally, some of the future opportunities that this versatile polymerization technique in an aqueous environment can offer are discussed, and it is anticipated that the aqueous RAFT polymerization field will continue to realize these, and other exciting opportunities into the future.
Topics: Polymerization; Polymers; Water; Solvents; Molecular Weight
PubMed: 35822936
DOI: 10.1002/marc.202200414 -
Journal of Food and Drug Analysis Jan 2020Hyaluronic acid (HA), a multi-functional material, has a high dispersion in molecular weight, and the functions of HA are determined through the size. Nevertheless,...
Hyaluronic acid (HA), a multi-functional material, has a high dispersion in molecular weight, and the functions of HA are determined through the size. Nevertheless, hyaluronic acid mixtures are not easily separated due to their polydispersity. In this study, a capillary electrophoresis strategy was developed for resolution of different molecular-weight HA without enzymatic digestion. Here, hyaluronic acid mixtures with low molecular weight (380 kD; LHA) and high molecular weight (2180 kD; HHA) were successfully resolved by the SDS integrated with low molecular-weight polymer in capillary electrophoresis. By optimizing experimental conditions, the separation of LHA and HHA was completed within 14 min. The optimal conditions were as follows: the running buffer was 25 mM borate buffer (pH 9.75) containing 30 mM SDS and 10% polyethylene glycol (MW: 8000); applied voltage was 20 kV (detector at cathode side) and separation temperature was set at 25 °C. The data of method validation showed that calibration plots were linear (r ≥ 0.9977) over a range of 10-50 μg/mL for LHA, and 40-200 μg/mL for HHA. In the evaluation of precision and accuracy for this method, the RSD and RE values were all less than 4.2%. This fascinating technique was successfully applied to the quality control of cosmetic and pharmaceutical containing different ratios of LHA and HHA, and it was feasible for serving as a tool to quantitatively analyze different sizes of HA for clinical survey.
Topics: Chromatography, Micellar Electrokinetic Capillary; Hyaluronic Acid; Molecular Weight; Polymers
PubMed: 31883604
DOI: 10.1016/j.jfda.2019.10.005 -
Biomacromolecules Oct 2020Osteoarthritic joints contain lower-molecular-weight (MW) hyaluronan (hyaluronic acid, HA) than healthy joints. To understand the relevance of this HA size effect for...
Osteoarthritic joints contain lower-molecular-weight (MW) hyaluronan (hyaluronic acid, HA) than healthy joints. To understand the relevance of this HA size effect for joint lubrication, the friction and surface structure of cartilage-emulating surfaces with HA of different MWs were studied using a surface force balance (SFB) and atomic force microscopy (AFM). Gelatin (gel)-covered mica surfaces were coated with high-MW HA (HHA), medium-MW HA (MHA), or low-MW HA (LHA), and lipids of hydrogenated soy l-α-phosphatidylcholine (HSPC) in the form of small unilamellar vesicles, using a layer-by-layer assembly method. SFB results indicate that the gel-HHA-HSPC boundary layer provides very efficient lubrication, attributed to hydration lubrication at the phosphocholine headgroups exposed by the HA-attached lipids, with friction coefficients (COF) as low as 10-10 at contact stresses at least up to = 120 atm. However, for the gel-MHA-HSPC and gel-LHA-HSPC surfaces, the friction, initially low, increases sharply at much lower pressures (up to 30-60 atm at most). This higher friction with the shorter chains may be due to their weaker total adhesion energy to the gelatin, where the attraction between the negatively charged HA and the weakly positively charged gelatin is attributed largely to counterion-release entropy. Thus, the complexes of LHA and MHA with the lubricating HSPC lipids are more easily removed by shear during sliding, especially at high stresses, than the HHA-HSPC complex, which is strongly adhered to gelatin. This is ultimately the reason for lower-pressure lubrication breakdown with the shorter polysaccharides. Our results provide molecular-level insight into why the decrease in HA molecular weight in osteoarthritic joints may be associated with higher friction at the articular cartilage surface, and may have relevance for treatments of osteoarthritis involving intra-articular HA injections.
Topics: Cartilage, Articular; Friction; Hyaluronic Acid; Lubrication; Molecular Weight; Synovial Fluid
PubMed: 32931261
DOI: 10.1021/acs.biomac.0c01151 -
Journal of Medicinal Chemistry Sep 2023Molecular complexity (MC) lacks a universal definition, but various studies address it in contexts ranging from ligand-receptor interactions to DNA sequencing, with the...
Molecular complexity (MC) lacks a universal definition, but various studies address it in contexts ranging from ligand-receptor interactions to DNA sequencing, with the overarching emphasis being its significance in synthetic organic chemistry and pharmaceutical research. Efforts to quantify MC in drug discovery have been numerous, but a unified approach remains challenging. Strategies based on graph theory, information theory, and substructural feature counts employed to gauge MC are often correlated to molecular weight (MW). Herbert Waldmann and his team introduced a new MC metric called the spacial score (SPS), which is based on factors like atom hybridization and stereoisomeric considerations. While SPS and its normalized version, nSPS, correlate with the natural product likeness score, they do not align with traditional chemical properties. We examined nSPS trends for approved drugs and found no significant changes in MC over eight decades, nor did nSPS capture drug innovation during that period. Furthermore, our analysis indicates that while the majority of approved drugs have an nSPS value between 10 and 20, this metric does not correlate with key drug properties like target bioactivity and oral bioavailability. Mirroring a chemist's intuitive sense of chemical complexity, nSPS addresses the need for a precise empirical tool while a universal definition of MC remains elusive.
Topics: Drug Discovery; Biological Products; Molecular Weight
PubMed: 37675804
DOI: 10.1021/acs.jmedchem.3c01507 -
Carbohydrate Research Aug 2022In the last decades, synthesis and design of low molecular weight organogelators has gained increasing attention due to their versatile use in, for example, cosmetics,...
In the last decades, synthesis and design of low molecular weight organogelators has gained increasing attention due to their versatile use in, for example, cosmetics, biomedicine and oil spill remediation. In this work, three potential gelators have been prepared from allylated d-mannose. Both the gelators and the corresponding gels formed were thoroughly characterized by crystallography, FTIR spectroscopy, SEM, rheometry and NMR spectroscopy, in solution and in solid state. The results showed that two of the compounds phase-selectively form gels with hydrocarbon solvents. The most promising gelator compound is alkene terminated, with the unsaturated end functionality not critical for gel formation, tentatively providing the possibility for customizing the gelation properties by further chemical modification. Alternatively, the alkene group could possibly be utilized as a linker for future coupling to carrier materials or surfaces to further increase the mechanical strength of the gel.
Topics: Alkenes; Gels; Mannose; Molecular Weight; Petroleum Pollution
PubMed: 35665623
DOI: 10.1016/j.carres.2022.108596 -
Food Research International (Ottawa,... Dec 2022Consumers are increasingly looking for new plant-based alternatives to substitute animal proteins in their diets but for some applications it can be difficult to achieve...
Consumers are increasingly looking for new plant-based alternatives to substitute animal proteins in their diets but for some applications it can be difficult to achieve the desired product microstructure using only plant proteins. One approach to facilitate structuring is to mix these plant-based ingredients with a polysaccharide. Here, the phase behaviour and microstructure of quinoa protein isolate (QPI) in mixture with maltodextrin (MD) of two dextrose equivalents (DE 7 and 2) were investigated. The binodals of both QPI-MD phase diagrams showed an atypical shape, where the concentration of MD in the QPI-rich phase and of QPI in the MD-rich phase increased with overall biopolymer concentration. Molecular weight distribution and microstructure analyses revealed that both maltodextrins fractionated between the phases and were probably entrapped within the volume-spanning protein network in the QPI-rich phase, indicating a depletion flocculation mechanism of phase separation. The pre-heating of QPI and the removal of salt from the systems resulted in similarly atypical phase diagrams. The approach presented contributes to our understanding of the phase behaviour of mixtures between plant proteins and polysaccharides, while the results suggest that the formulation of plant-based products of predictable properties may be more challenging than anticipated.
Topics: Animals; Chenopodium quinoa; Polysaccharides; Plant Proteins; Molecular Weight
PubMed: 36461320
DOI: 10.1016/j.foodres.2022.112064 -
Molecules (Basel, Switzerland) Jul 2022Molecular interaction analysis is an essential technique for the study of biomolecular functions and the development of new drugs. Most current methods generally require...
Molecular interaction analysis is an essential technique for the study of biomolecular functions and the development of new drugs. Most current methods generally require manipulation to immobilize or label molecules, and require advance identification of at least one of the two molecules in the reaction. In this study, we succeeded in detecting the interaction of low-molecular-weight (LMW) compounds with a membrane protein mixture derived from cultured cells expressing target membrane proteins by using the size exclusion chromatography-mass spectrometry (SEC-MS) method under the condition of 0.001% lauryl maltose neopentyl glycol as detergent and atmospheric pressure chemical ionization. This method allowed us to analyze the interaction of a mixture of medicinal herbal ingredients with a mixture of membrane proteins to identify the two interacting ingredients. As it does not require specialized equipment (e.g., a two-dimensional liquid chromatography system), this SEC-MS method enables the analysis of interactions between LMW compounds and relatively high-expressed membrane proteins without immobilization or derivatization of the molecules.
Topics: Chromatography, Gel; Chromatography, Liquid; Mass Spectrometry; Membrane Proteins; Molecular Weight
PubMed: 35956840
DOI: 10.3390/molecules27154889 -
Journal of Biochemistry Sep 1975The intrinsic viscosity ([eta]) and the molecular weight (M) by sedimentation equilibrium were determined for hyaluronic acids of low (M=104--7.2X10(4)) and high...
The intrinsic viscosity ([eta]) and the molecular weight (M) by sedimentation equilibrium were determined for hyaluronic acids of low (M=104--7.2X10(4)) and high (M=3.1X10(5)--1.5X10(6)) molecular weights. Double logarithmic plot of [eta] against M gave different lines for the two groups. The relationship between [eta] and M was [eta]=3.0X10(6)XM1,20 for the former and [eta]=5.7X10(-4)XM0.46 for the latter group. The molecular weight at the point of intersection of the two lines was about 1.5X10(5). The rheological behavior of the hyaluronic acids below M=2.1X10(4), for which the value of reduced viscosity was independent of concentration, was different from that of the hyaluronic acids above M=5.1X10(4), for which the value of reduced viscosity increased with concentration.
Topics: Female; Hexosamines; Humans; Hyaluronic Acid; Mathematics; Molecular Weight; Pregnancy; Protein Conformation; Umbilical Cord; Viscosity
PubMed: 1225913
DOI: 10.1093/oxfordjournals.jbchem.a130935